Study of Viability and Seed Structure of Shallot

In Indonesia, shallot cultivation finds difficulties to produce high viability seed. That low viability is caused by the abnormality of seed＇s structure. Normal shallot seeds have seed structure that consists of： testa, endosperm, and embryo. Normal embryo has curved shape which it has one cotyledon in endosperm. This research purpose is to find shallot viability and structure that is cultivated in tropic area, especially in Indonesia. This research is a deep observation research about water level, seeds viability and seeds structure monitoring by using microscope. To make a clearance about seeds structure composition, seeds are mixed with tetrazolium salt. Monitoring result shows that seed water level at harvest time is 18%, laid away at one month age is 13%, two months age is 12% and three months age is 10%. Seed viability at harvest until twenty nine days, seed that is germinated around 8%. At two months viability seed laid age until twenty two days is 36.6%. Meanwhile three months age laid viability test is done with germination boost compounding shows that IAA is able to fasten germination. At IAA treatment viability seeds are 17.25% that is followed with GA3 treatment around 13%. Another boosting substance that it＇s viability is only below 4%. Low viability is also proved by the seed structure. The result shows that mostly, the seeds has abnormal structure.

Influence of specimen uniformity on mechanical behaviour of unsaturated soil

Pressure plate instrument is employed during drying, and unconfined compressive strength test is performed on the unsaturated specimen. Curves of shear force versus shear displacement, and curves of saturation degree versus time are investigated. The results show that the specimens with similar curves of saturation degree versus time have nearly identical mechanical behavior. In particular, the uniform specimens should be chosen within the lower equilibrium saturation degree because steady test results are presented. Further, the conclusion is verified by the repeated test. Thus, the method for distinguishing the uniform unsaturated specimen is obtained. In the light of the method, an improved test process is proposed. The uniform specimens should be chosen by this method under the specific matric suction, and then shear tests are carried out on the chosen unsaturated specimen. Namely, initial value of unsaturated soil is not zero matric suction but a specific suction.

TESTING k-EDGE-CONNECTIVITY OF DIGRAPHS

This paper presents an algorithm that tests whether a given degree-bounded digraph is k-edge-connected or E-far from k-edge-connectivity. This is the first testing algorithm for k-edge- connectivity of digraphs whose running time is independent of the number of vertices and edges. A digraph of n vertices with degree bound d is ε-far from k-edge-connectivity if at least εdn edges have to be added or deleted to make the digraph k-edge-connected, preserving the degree bound. Given a constant error parameter ε and a degree bound d, our algorithm always accepts all k-edge-connected digraphs and reiects all digraphs that is ε-far from k-edge-connectivity with orobabilitv at least 2/3.It runs in O（d（εd^-c）^k logεd^-1O）（c〉1 is a constant）time when input digraphs are restricted to be （k-1）-edge connected and runs in O（d（εd^-ck）^klogεd^-kO）（c〉1 is a constant）time for general digraphs.

Experimental study on uniaxial time-dependent ratcheting of a polyetherimide polymer

The uniaxial ratcheting behavior of a polyetherimide (PEI) polymer 'TECAPEI' was studied using stress-controlled cyclic loading at room temperature, including both cyclic tension-compression with non-zero tensile mean stress and tension- unloading tests. The experimental observations were focused on the time-dependent ratcheting of the PEI polymer revealed in cyclic tests at diverse stress rates and with different peak stress holding times. The results showed that the PEI polymer shows obvious ratcheting deformation; i.e., the ratcheting strain accumulates progressively in the tensile direction during stress- controlled cyclic tests with non-zero mean stress. The ratcheting is highly dependent on the applied mean stress and stress am-plitude, and is also characterized by a strong time-dependency during the cyclic stressing at diverse stress rates and with different peak stress holding times. The time-dependent ratcheting of the PEI polymer is caused mainly by its remarkable viscosity. A comparison of the ratcheting occurring before and beyond the ultimate stress point of the PEI polymer showed that the ratcheting beyond the ultimate stress point is more significant than that occurring before that point.